The man who bore much of the blame for last year’s schools tests marking fiasco has hit back at ministers.

Dr Ken Boston, who quit as chief executive of the Qualifications and Curriculum Authority (QCA), denounced their account of events as “fiction”.

Former exam board boss attacks ministers over last year’s school test marking fiasco

He has strongly challenged evidence given by Children’s Secretary Ed Balls and schools minister Jim Knight in the Commons and to the official inquiry into what went wrong.

According to extracts of a letter to the Commons Children, Schools and Families Committee, he rejected what he said were attempts by ministers to portray him as “complacent and disengaged”.

Dr Boston, who is due to appear before the committee, said that in evidence to Lord Sutherland’s inquiry Mr Knight had wrongly claimed he was present at one meeting last June when the Sats tests were discussed when he had not even been invited.

He also challenged the inquiry’s finding – read out by Mr Balls in the Commons – that ministers had “usually pressed” him for answers and that the QCA had given “strong reassurances” that the tests were on track.

“This too is fiction,” he said.

He said he had only met ministers twice in the months leading up to the tests.

At the first meeting the subject had been mentioned “only briefly”, although he acknowledged he had subsequently given an assurance to Mr Balls that problems with markers had been overcome “on the basis of evidence which I believed to be sound”.

“I was not asked to meet directly with the schools minister in the months leading up to the delivery failure at the end of June, including the critical marking period in the final eight weeks. Nor was I being ‘pressed’ by ministers for answers on the telephone or by email,” Dr Boston wrote.